Sequencing insect genomes could help to unlock new insights into pest behaviour and lead to a new level of targeted, more ecological pest control, according to researchers at top agricultural research centre, Rothamsted Research

Researchers at the centre, which is the longest-running agricultural research institute in the world, teamed up with major industry players Syngenta and Bayer to sequence over 20 genomes of insects over the past five years, including some of the most prolific pest threats faced by farmers.

Before this, detailed genomes had been assembled for only a handful of the planet’s one million plus insect species – something that lead researcher Linda Field called a “real stumbling block” to research.

Field, who is a leading insect molecular biologist and professor emerita at Rothamsted, told EURACTIV that besides having a “huge benefit” to the world of entomology, the sequenced genomes, which have been made publicly available via a database, could revolutionise targeted pest control.

This is because genome maps can reveal key differences underpinning the biological mechanisms of pest species compared to other insects.

Knowledge is power

For instance, thanks to years of painstaking research, researchers already know that aphids, a serious plant pest that transmits several diseases, have sodium channels that are very different to other insects.

“But we got that the hard way by cloning both and looking at them, whereas now you could go into a database and see there’s a difference in the sodium channel, calcium channel or the nicotinic receptor, and if you could design a molecule in a computer that would bind to one and not the other to get selectivity,” she explained.

Alternatively, the database could help reveal which insects can detoxify certain compounds, meaning that the team can design targeted molecules – for instance, one that a bee could metabolise and be immune to but could kill a pest, she explained.

But the genomes may also help to develop non-chemical pest control methods, such as manipulating insect behaviour, by focusing on the genes that control how insects find mates and host plants, hence shepherding them away from crops.

“There’s a whole area of an even just simple use of pheromones to distract insects away, and you might be able to do that much more in a controlled way if you knew exactly how the insects [are] detecting these in the first place,” she said.

“Having the genomes [means] we can know a lot more about how those how the antennae actually detect those volatile,” she explained, adding that this is “another area that will be opened up by having the genomes”.

Targeted control

In this way, the researcher hopes the database will “open up the use of chemical ecology”, which – crucially – can help develop pest control that is not only species-specific but also less likely to incite resistance evolving in their target species – a serious, and growing, problem for farmers and often the reason for excessive pesticide use.

This is key, as it means that “when farmers need to firefight, you’ve still got something that works”.

Worldwide, some 600 species of pests have already developed some level of pesticide resistance, reducing the efficacy of options available for pest management.

For Field, unlocking the information held in these insect genomes could help steer the agricultural sector towards the future of pest control, which, for her, is one that takes a whole systems approach” involving a combination of selective chemistry alongside more resilient crops, healthier biodiversity and a deeper ecological understanding.